The dual role of a bHLH protein: Is SCRM1 / ICE1 an integrator of cold-stress and stomatal fate signaling?

bHLH 蛋白的双重作用：SCRM1 / ICE1 是冷应激和气孔命运信号的整合者吗？

• 批准号: 179169260
• 负责人: Dr. Robin Jonathan Horst
• 金额: --
• 依托单位: Department of Biology
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/179169260?language=en
• 关键词: dual; role; bHLH; protein; SCRM1

The formation of functional cell patterns in multicellular organisms requires specific cell-fate determinants. The outcome of this formation is influenced by the environment. Stomatal development in the plant Arabidopsis thaliana provides an easily accessible model to study the integration of environmental cues into developmental processes. Stomata are valves in the plant epidermis that regulate the gas exchange between the air and the intercellular spaces. The number of stomata per leaf area is influenced by CO2 and light intensity, and systemic signaling is thought to be involved in controlling stomatal development in response to these cues. Two basic helix-loop-helix (bHLH) transcription factors (TFs), SCRM1 and 2, play a key role in regulating the entry of protodermal cells into the stomatal lineage and in the progression through the stomatal lineage that ultimately forms mature stomata. SCRM1 interacts with three known bHLH TFs (SPCH, MUTE and FAMA) that positively regulate sequential steps during stomatal cell-state progression, but regulators of SCRM-activity in the stomatal lineage are unknown. The epidermis of dominant scrm-D mutants develops only stomata, so scrm-D provides a basis for a genetic screen for SCRM regulators. The finding that SCRM1 is ICE1, a regulator of freezing tolerance, suggests a dual role of SCRM1, which may act as an integrator of abiotic stress signaling and stomatal development. This project aims at unraveling the molecular mechanisms that regulate both functions of SCRM1 and at understanding the impact of cold signaling on stomatal development. It will give insight into how environmental cues are integrated into developmental processes. Three specific aims are: 1: Determine the role of systemic cold signaling in stomatal development. 2: Unravel mechanisms that regulate SCRM1 or ICE1 action on the post-translational level. 3: Identify novel factors that regulate the dual function of SCRM1.

多细胞生物体中功能细胞模式的形成需要特定的细胞命运决定因素。这种形成的结果受到环境的影响。拟南芥植物的气孔发育为研究环境信号与发育过程的整合提供了一个容易获得的模型。气孔是植物表皮中调节空气和细胞间隙之间气体交换的阀门。每叶面积上的气孔数受二氧化碳和光照强度的影响，系统信号被认为参与了对这些信号的响应来控制气孔的发育。两个基本的螺旋-环-螺旋转录因子，SCRM1和2，在调节原胚层细胞进入气孔谱系和通过气孔谱系最终形成成熟气孔的过程中发挥关键作用。SCRM1与三个已知的bHLHTF(SPCH、MUTE和FAMA)相互作用，这三个因子积极地调节气孔细胞状态进展过程中的连续步骤，但气孔谱系中SCRM活性的调节尚不清楚。显性SCRM-D突变体的表皮只发育气孔，因此SCRM-D为SCRM调节基因的筛选提供了基础。这一发现表明，SCRM1具有双重作用，可能是非生物胁迫信号和气孔发育的整合因子。本项目旨在揭示调控SCRM1功能的分子机制，并了解冷信号对气孔发育的影响。它将让我们深入了解环境线索是如何融入发展过程的。三个具体目标是：1：确定系统冷信号在气孔发育中的作用。2：揭示在翻译后水平上调节SCRM1或ICE1作用的机制。3：确定调节SCRM1双重功能的新因素。